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Old 12-11-2005, 11:35 PM   #15
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Gotta say that the retro curvey moho towing the cool modern boxey Scion is a very cool combination.
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Old 12-12-2005, 12:11 AM   #16
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Tim,
I too have some very small bolts which appear to hold the receiver on, but, when I looked more closely I found that in fact my receiver is welded in place with a very stout weld.

Also, the tow bar/auto combination puts essentially no weight on the rear of the MH (about half the weight of the tow bar less than 15 pounds). The tow bar moves up and down and twists (rotates) freely so the auto and the MH can move independently. The tow bar merely provides a connection so that the two vehicles push and pull each other.
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Old 12-12-2005, 08:06 AM   #17
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Quote:
Originally Posted by guy99
Tim,
I too have some very small bolts which appear to hold the receiver on, but, when I looked more closely I found that in fact my receiver is welded in place with a very stout weld.

Also, the tow bar/auto combination puts essentially no weight on the rear of the MH (about half the weight of the tow bar less than 15 pounds). The tow bar moves up and down and twists (rotates) freely so the auto and the MH can move independently. The tow bar merely provides a connection so that the two vehicles push and pull each other.
Thanks very much for this information. I haven't even slid under the hitch yet to study the attachment, other than to look at the small bolts. I hope mine is put on with welds also. Thanks also for the explanation of the tow bar setup. I knew the principle, but hadn't really thought about the weight applied to the rear of the MH. My obstacle to a tow bar setup is money. Also, I've heard from enough dolly towers to be reasonably satisfied that the setup works, and I can get brakes with the dolly. I really appreciate your time and expertise. Please let me know if you have other information or ideas that will help me as I decide about this - or any other issue. I'm very new to MHs. I've pulled trailers for 30 years, but, as you know, it's not the same . Thanks again, Tim
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Old 12-12-2005, 10:54 AM   #18
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the Scion is a stick I presume? Can their automatics be flat towed also? We are considering one of those for our next ride.
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Old 12-12-2005, 11:15 AM   #19
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Alan,
Yes the Scion is a 5 speed. Per Remco the automatic can not be made flat tow-able.
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Old 12-12-2005, 02:56 PM   #20
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Receiver welds

Quote:
Originally Posted by guy99
Tim,
I too have some very small bolts which appear to hold the receiver on, but, when I looked more closely I found that in fact my receiver is welded in place with a very stout weld.

Also, the tow bar/auto combination puts essentially no weight on the rear of the MH (about half the weight of the tow bar less than 15 pounds). The tow bar moves up and down and twists (rotates) freely so the auto and the MH can move independently. The tow bar merely provides a connection so that the two vehicles push and pull each other.
guy99, Just got a chance to slide under the coach and take a close look at the receiver. You are absolutely correct about the welds in addition to the bolts. I couldn't see them by just leaning down in my previous explorations. That should be plenty secure for towing a four wheel on the ground or a dolly, as long as it's not over about 5,000 lbs. I'm estimating, of course, and the manual still says 2,000 lbs. I am NOT recommending towing 5,000 lbs, just the amount of weight the receiver can likely take. Besides, vertical weight (pushing down) is murder on the tag axles, so the tongue weight on the pulled object becomes critical, as you know. However, the manual also claims the receiver is a Class I, which it's not. Thanks for getting my curiosity up. I wouldn't have discovered the welds until I was well into beefing up the thing. Not necessary for what I'm planning, of course. Thanks again ,

Tim
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Old 12-13-2005, 09:40 PM   #21
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Tim,
The consensus of the group on the Forum seems to be that the reason for the low towing rating of the classic motorhomes is the frame extension which moves the hitch far behind the wheels and the resulting long moment arm. The frame extension on my 310 isn't very long. Do you know if your coach has the same wheel base as a 345?, if it does I imagine your hitch is a long way behind your rear wheels.

It's not clear to me whether the concern about the moment arm has to do whith breaking the frame or stability while driving.
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Old 12-13-2005, 10:12 PM   #22
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Quote:
Originally Posted by guy99
Tim,
The consensus of the group on the Forum seems to be that the reason for the low towing rating of the classic motorhomes is the frame extension which moves the hitch far behind the wheels and the resulting long moment arm. The frame extension on my 310 isn't very long. Do you know if your coach has the same wheel base as a 345?, if it does I imagine your hitch is a long way behind your rear wheels.

It's not clear to me whether the concern about the moment arm has to do whith breaking the frame or stability while driving.
My understanding is that the concern is the moment arm in turns. The extension isn't strong enough to handle a lot of weight pulling at an angle and can rack the frame behind the axles. I would be concerned about towing a 3000# vehicle. That is 50% above the limit set by Airstream.
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Old 12-14-2005, 03:46 PM   #23
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370 Wheelbase and Overhang

guy99 and Minnie's Mate,

The frame extension on the 370 is less than 12", and only 3" to the receiver. In addition, this model was built on a Gillig chassis instead of the C-30 used by most of the other models. The frame is almost 8" tall, and the height of the coach is a little over 1 and 1/2 feet taller than the other models in 1989 - mostly due to the Gillig chassis and the way the coach body is mounted on that chassis. I don't think frame extension should be an issue.
However, it is a LONG vehicle The wheelbase is 218" vs 204" for the 345, so it's RELATIVELY less 'percentage' overhang than the 345. Not to say it's not a lot of overhang - it definitely is. I'm not clear what a "moment arm" is, but the Gillig manual shows a "Transverse Road Assembly" that is bolted on pivots from the top of the drive axle to the frame. It's designed to lower twist of the drive axle during hard torque situations. Is that what a moment are is? Anyway, just a few other things - I have a 5.29 rear axle, which is terrible for interstate speeds, but great for in-town and mountains. The extremely low gearing is very helpful with low end torque. I plan to add a Gear Vendors under/over drive to help me run interstate speeds at rpms that don't race the whole drive system. Currently, I keep things below 3,000 rpms, which limits me to 60 mph - a good speed anytime, but not practical when one has to travel interstates once in a while.

Finally, I have gotten private emails from a number of members of the forum who have towed up to 4,000 lb vehicles for many years without problems. That doesn't mean the 370 will do as well, but I have paid attention to their advice, just as I do with everyone who contributes. I greatly appreciate all advice and information on this issue. Thanks so much for helping. I welcome any further comments or suggestions.

Tim
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Old 12-15-2005, 01:10 AM   #24
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Basically, the moment arm of a hammer is the force applied to the handle multiplied times the length of the handle. The longer the handle, the greater the force exerted on the nail by the force applied to the tip of the handle. In the case of the motorhome, the length of the overhang multplied by the lateral or sideways force in the turn caused by the toad. The greater the overhang, the greater the force applied to the area of the frame directly behind the axel. This leverage is what would cause the frame to rack. In the motor home example, the center of the axel becomes the piviot point for the moment arm. In the hammer example, the head of the hammer is the pivot point for the hammer. This comparison may be too simplistic to be accurate for engineers and physicists. This is not to say your coach can't do it, just my understanding of why AS doesn't recommend more than 2,000#.
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Old 12-15-2005, 07:59 AM   #25
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Quote:
Originally Posted by Minnie's Mate
Basically, the moment arm of a hammer is the force applied to the handle multiplied times the length of the handle. The longer the handle, the greater the force exerted on the nail by the force applied to the tip of the handle. In the case of the motorhome, the length of the overhang multplied by the lateral or sideways force in the turn caused by the toad. The greater the overhang, the greater the force applied to the area of the frame directly behind the axel. This leverage is what would cause the frame to rack. In the motor home example, the center of the axel becomes the piviot point for the moment arm. In the hammer example, the head of the hammer is the pivot point for the hammer. This comparison may be too simplistic to be accurate for engineers and physicists. This is not to say your coach can't do it, just my understanding of why AS doesn't recommend more than 2,000#.
Thanks so much for the explanation. I understand fully what you are saying now. I'm glad you kept it simplistic. I agree with you completely that the 2,000 lb recommendation is a real concern. I've been working on asking questions about the rating since I first got involved with my 370 a year and a half ago. In my 30 years of trailer towing, I could only afford a correctly rated tow vehicle in the last 12 years. Before that I was always over the manufacturer's limits. I'm not advising that, but I had no choice. Of course, I always beefed up my tow vehicles the best I could with larger radiators, more frequent oil changes, air shocks, and even a rear axle gear set change. I never broke down on a trip. Now, I know the situation with the MH is not the same issue. The overhang is a real concern of mine. I've heard from a number of 345 and even a 370 owner who have all towed loads above 2,000 lbs with no problems. I would like to know if anyone has experienced this frame twisting with a load of, say, 3,000 lbs. Again, I'm not saying it's the best idea, but I can't afford a lighter vehicle, and my camping habits tend toward staying in one place for weeks at a time. Towing a car is the only logical way to get around once I get to a campground. It's the old "benefit/risk" issue, I suppose. I need the car, but I don't want to ruin my rig or get someone killed in the process. Thanks for your help.
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Old 12-24-2005, 11:09 AM   #26
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Towing

I have for ten years towed a full sized vehicle behind my 345 diesel. I towed my wife's Taurus accross the country, my own Explorer as well, and now we tow a 05 VW Jedda Diesel. I have encountered no problems at all. I use a tow dolly made in Iowa with a long tongue which gives a lot of swing up and down. (Demco).
The only trouble I have had is going through a swale, sometimes the hitch will bottom out and scrape the ground. But that happens whether I am towing or not.
I at first understood that Airstream was worried about the strength of the hitch, but it is solidly attached (welded) to several frame members.
My feeling is that if one is careful, you can tow whatever you want. Just don't put a lot of stress on it. Like jerk it around.
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Old 12-24-2005, 11:21 AM   #27
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Quote:
Originally Posted by cooperhawk
I have for ten years towed a full sized vehicle behind my 345 diesel. I towed my wife's Taurus accross the country, my own Explorer as well, and now we tow a 05 VW Jedda Diesel. I have encountered no problems at all. I use a tow dolly made in Iowa with a long tongue which gives a lot of swing up and down. (Demco).
The only trouble I have had is going through a swale, sometimes the hitch will bottom out and scrape the ground. But that happens whether I am towing or not.
I at first understood that Airstream was worried about the strength of the hitch, but it is solidly attached (welded) to several frame members.
My feeling is that if one is careful, you can tow whatever you want. Just don't put a lot of stress on it. Like jerk it around.
Copperhawk,

Your comments reflect what I've heard most often from people who have towed with these MoHos. I appreciate your sharing your experiences. No one has related experiences towing that would lead me to believe there's a major issue, if one takes proper precautions as with towing anything. My "master plan" is to put a Gear Vendors under/over drive unit on my tranny since my rear Gillig axle is so low (5.29). That will effectively give me a 6-speed transmission with an overdrive. That should allow me to cruise interstates at the speed limit without revving my engine so much, and at the same time retain the torque from the Ford 460 and very low rear axle for in town and mountain climbing. Thanks again for the advice.

Tim
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Old 04-10-2006, 05:43 PM   #28
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So I'm trying to figure out where the weakness is in the AS and why the tow limit is 2,000 lbs.

From what I gather it's the long length from the rear duals to the ball (moment arm).

I can imagine turning in a tight circle too fast where the trailer is almost jack knifed. if you slammed on the brakes with a 3,000 trailer, it would bend the frame behind the rear axle. Maybe even kink the body?

Besides re-inforcing the reciever to the frame, is there a way to beef up the frame behind the rear axle?

If you made the RV stronger would you still be illegal by going over the limits set by the manufacturer?

I am totally comfortable overloading a vehicle, but with 11 years of truck driving experience I've learned there's more to it than just smashing down your suspension. If you get into a wreck when you are overloaded, you're toast.

BTW, I'm considering the purchase of a classic MoHo, and i have to pull a 2800-3200lb 6x12 wells cargo MC trailer.

Thanks,
Kevin
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